Tablet terminals including smartphones, cellular phones, personal handyphone systems (PHS), and personal digital assistants (PDA) have been widely used. To improve operability of such tablet terminals, a user interface that combines eye-gaze input and contact input has been developed.
In briefly explaining the foregoing, the user interface receives movement of a cursor displayed on a touch panel by the move of eye gaze of a user. When a given area on the touch panel is subsequently touched, the user interface then selects an object at which the cursor is aimed. In this way, the user interface tries to make the user operate the touch panel in a one-handed operation with a hand holding the tablet terminal. An example of such user interface is described in a non-patent document: T. Nagamatsu, et al., “MobiGaze: Development of a Gaze Interface for Handheld Mobile Devices”, CHI 2010: Work-in-Progress, Apr. 12-13, 2010.
The above-described conventional technology, however, may increase a strain on the eyes of the user as described in the following.
More specifically, when a human sees things, the eye gaze does not stay at a certain place and generally moves around the periphery of a target, and thus fixing the eye gaze may cause an eye strain. The above-described user interface, however, forces to fix the eye gaze on the cursor so as to move the cursor to the target object. As a result, the above-described user interface is likely to increase the strain on the eyes of the user. Furthermore, when aiming the cursor to the target object by eye gaze, as the target object becomes smaller, the user may move the eye gaze more minutely. As a consequence, depending on the size of the object displayed on the touch panel, the strain on the eyes of the user may further be increased.